This application claims the priority of German Application No. 196 11 579.5, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a device for identifying objects and, more particularly, to a device for identifying objects resting on a carrier that are moved along a conveyor line by a conveyor and which undergo various machining processes along the conveyor line. A marking carrier is connected with the object and a fixed reading device is provided for the marking carrier.
It is known, for example, to hang a marking carrier in a vehicle body during the manufacture of a vehicle. The vehicle body passes through various painting processes. These painting processes also involve dipping the vehicle body completely in paint baths. The painting processes are followed by drying processes in which the vehicle body is heated to temperatures of 180xc2x0 C. for example.
The handling of the marking carrier in the known device is cumbersome since the marking carrier must be hung in place before the paint treatment and must then be removed from the vehicle again. There is also the risk of twisting, so that it is no longer, or not readily, possible for a reading device to identify the marking carrier. Finally, the reading device is also located in the work area. The line of sight between the marking carrier and the reading device can be broken by objects in the visual field of the reading device. Since as a rule several reading devices are used during the various processing steps, which then might possibly be completely or partially ineffective as a result, there is the risk of an insufficient monitoring of the respective vehicle throughout the entire processing chain.
There is therefore needed a device of the above-mentioned type or identifying objects that permits reliable recognition of the marking carrier in a manner that is simple in design and straightforward in performance.
The present invention meets these needs by a device for identifying objects and, more particularly, to a device for identifying objects resting on a carrier that are moved along a conveyor line by a conveyor and which undergo various machining processes along the conveyor line. A marking carrier is connected with the object and a fixed reading device is provided for the marking carrier. The marking carrier is mounted on the carrier and the reading device is located below the conveyor line.
By placing the reading device at the bottom of the conveyor line, the risk of inadvertent interruption of the line of sight between the marking carrier and the reading device is eliminated. At the same time, the rigid mounting of the marking carrier on the carrier permits correct visual orientation with respect to the reading device. The permanent connection with the carrier makes special handling of the marking carrier superfluous. Instead, the marking carrier always moves with the carrier and is also subjected, together with the carrier, to subsequent treatment, in the form of paint removal for example. Of course, a marking carrier of this kind must be especially mechanically strong.
The reading device can be, for example, a camera with an image processing device connected thereto. Alternatively, a bar code reader can be used, provided the marking carrier is provided with a bar code.
The use of a camera is advantageous if the marking carrier is made in an especially simple fashion out of sheet metal that is provided with a punched code. The image processing device is then designed as a conventional decoding device, for a punched code produced by a standard method for example.
To improve the optical scanning of the marking carrier, an illuminating device for the marking carrier can also be located below the conveyor line. The illuminating device can be switched on constantly or only when the marking carrier is in the vicinity.